90 likes | 309 Views
SYNTHESIS OF ATP. PETER MITCHELL AND JAGENDORF AND URIBE. PETER MITCHELL. PRIOR KNOWLEDGE The energy of electron transfer was stored as a stable high potential intermediate, a chemically more conservative concept. (Encyclopedia Britannica Online, Nov. 2010)
E N D
SYNTHESIS OF ATP PETER MITCHELL AND JAGENDORF AND URIBE
PETER MITCHELL • PRIOR KNOWLEDGE The energy of electron transfer was stored as a stable high potential intermediate, a chemically more conservative concept. (Encyclopedia Britannica Online, Nov. 2010) The biochemical mechanism of ATP synthesis by OXPHOS was unknown (ibid) Energy was carried down the respiratory chain by an unknown high- energy intermediate compound formed during oxidation
Continuation.. The energy derived from the intermediate compound was thought to form a universal energy currency known as ATP
EXPERIMENT CONDUCTED • Theoretical part: Scientists were unclear about the way high energy intermediate compound worked to create ATP. He imagined that the unbalanced proton amount would be balanced by having the protons go through an enzyme catalyzing ADP to ATP (Douglas Allchin, n.d) As the chemical gradient is created, the protons make it possible for the catalyzing reaction of ADP to ATP. Protons from the inter mitochondrial membrane space are carried back to the matrix where ATPase uses the energy of H+ from the chemical gradient to produce phosphorylize ADP to ATP Example of NADH and FADH with pulley illustration. The carrying of protons from NADH and FADH from one side of the mitochondrial membrane to the intermembrane space through osmosis
Practical Experiment • Using a rat liver mitochondria, he calculated the ph of the intermembrane space and the mitochondrial matrix. They also measured the pH of the intermembrane as H+ protons were moved into the ATPase. The result was that the pH decreased as a proton was removed from the intermembrane space. It was also discovered that the return of protons via ATPase used up the pH and electric gradients energy
Independent Variable: the pH of the intermembrane space • Dependent variable: the amount of ATP formed • Control Variable: having the same pH on both sides of the mitochondrial membrane.
Conclusion • The chemical gradient formed and energy from the protons is used by the ATPase enzyme for the phosphorylation of ADP to ATP • This led to the Chemiosmotic theory • He linked his experiment to how plants synthesize ATP.
References • Thomson Gale, 2005- 2006, http://www.bookrags.com/biography/peter-d-mitchell-wob/ • Douglas, Allchin, n.d, http://www1.umn.edu/ships/db/mitchell.pdf • http://www.ncbi.nlm.nih.gov/books/NBK21208/ • http://en.wikipedia.org/wiki/Chemiosmosis
Doc Kaisers Microbiology Home Page, http:/http://student.ccbcmd.edu/~gkaiser/biotutorials/energy/atpsynthase_il.html • http://bcs.whfreeman.com/thelifewire/content/chp07/0702002.html